The present invention relates to a method and apparatus for forming handle grips utilized on golf clubs, racquets, baseball bats and other devices employing handles that are subject to shock when such devices are impacted.
An earlier grip of this type shown in my U.S. Pat. No. 5,730,669, issued Mar. 24, 1998 on my application Ser. No. 08/787,828 utilizes a polyurethane layer bonded to a felt layer to define a unitary strip which is spirally wrapped about the handle of a golf club, racquet or the like to conform to the external configuration of such handle. The side edges of such grip utilize recessed, sidewardly and downwardly curved reinforced side edges along the length of the polyurethane-felt strip. Such reinforced side edges inhibit unraveling of the strip from the handle, enhance the frictional grip of the user and provides an improved appearance over existing grips. Where the grip is applied to golf clubs it reduces the interference with other golf clubs as a club is withdrawn from a golfer's bag. In such earlier grips the reinforced side edges were formed by urging an electrically heated platen against the side edges of the polyurethane layer of the strip so as to compress such side edges and thereby increase the density and hence the strength of the polyurethane layer in the vicinity of the side edges. A method of forming a polyurethane-felt grip of this type utilizing an electrically heated platen is disclosed in my above-identified U.S. Pat. No. 5,730,669. While the electrically heated platen system provides satisfactory results, the rate of production of polyurethane-felt strips utilizing applicant's heat-compressed reinforced side edges was limited, since movement of the strip relative to the platen was intermittent. Additionally, it was difficult to maintain the temperature of the entire surface of the platen contacting the strip along the length of the platen to the necessary magnitude to insure adequate compression of the polyurethane, particularly since the platen tends to cool off during its reciprocation relative the strip.